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At least 1,513 records · Page 84
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

Design and Prototyping of the Electron Ion Collider Electron Storage Ring 591 MHz Elliptical SRF Cavity

The Electron Ion Collider (EIC) is a new nuclear phys-ics research facility to be constructed at Brookhaven Lab (BNL). It consists a few accelerator complexes, each re-quires some different SRF and RF systems. Among them, the electron storage ring?s (ESR) 591 MHz fundamental RF system is one of the most challenging. This 17 cavi-ties system will handle a variable beam current of up to 2.5 A, and replenish up to 10 MW of beam power losses from both synchrotron radiation (SR) and high-order modes (HOM). In this paper, we will report the progress and findings of the ongoing design and prototyping of this cavity.

Guo, J.↗
DOE OSTI2020

Study of Fluctuations in Undulator Radiation in the IOTA Ring at Fermilab

We study turn-by-turn fluctuations in the number of emitted photons in an undulator, installed in the IOTA electron storage ring at Fermilab, with an InGaAs PIN photodiode and an integrating circuit. In this paper, we present a theoretical model for the experimental data from previous similar experiments and in our present experiment, we attempt to verify the model in an independent and a more systematic way. Moreover, in our experiment we consider the regime of very small fluctuation when the contribution from the photon shot noise is significant, whereas we believe it was negligible in the previous experiments. Accordingly, we present certain critical improvements in the experimental setup that let us measure such a small fluctuation.

43 PARTICLE ACCELERATORS↗
DOE OSTI2022

Waker Experiments at Fermilab Recycler Ring

Attaining high-intensity hadron beams is often limited due to the transverse collective instabilities, whose understanding is thus required to see and possibly extend the intensity limitations. To explore such instabilities, a novel artificial wake system, the waker, has been built and tested at the Fermilab Recycler Ring (RR). In this report, we show recent upgrades of the waker. Also, we present experimental studies of instabilities at various space charge and wake parameters.

43 PARTICLE ACCELERATORS↗
DOE OSTI2022

Machine Learning for Slow Spill Regulation in the Fermilab Delivery Ring for Mu2e

A third-integer resonant slow extraction system is being developed for the Fermilab’s Delivery Ring to deliver protons to the Mu2e experiment. During a slow extraction process, the beam on target is liable to experience small intensity variations due to many factors. Owing to the experiment’s strict requirements in the quality of the spill, a Spill Regulation System (SRS) is currently under design. The SRS primarily consists of three components - slow regulation, fast regulation, and harmonic content tracker. In this presentation, we shall present the investigations of using Machine Learning (ML) in the fast regulation system, including further optimizations of PID controller gains for the fast regulation, prospects of an ML agent completely replacing the PID controller using supervised learning schemes such as Long Short-Term Memory (LSTM) and Gated Recurrent Unit (GRU) ML models, the simulated impact and limitation of machine response characteristics on the effectiveness of both PID and ML regulation of the spill. We also present here nascent results of Reinforcement Learning efforts, including continuous-action soft actor-critic methods, to regulate the spill rate.

43 PARTICLE ACCELERATORS↗
DOE OSTI2022

TOLERANCES OF CRAB DISPERSION AT THE INTERACTION POINT IN THE HADRON STORAGE RING OF THE ELECTRON-ION COLLIDER

The Electron Ion Collider (EIC) presently under construction at Brookhaven National Laboratory will collide polarized high energy electron beams with hadron beams with luminosities up to 10^34 cm^?2 s^?1 in the center mass energy range of 20-140 GeV. Due to the detector solenoid in the interaction region, the design horizontal crabbing angle will be coupled to the vertical plane if uncompensated. In this article, we study the tolerances of crab dispersion at the interaction point in the EIC Hadron Storage Ring (HSR). Both strong-strong and weak-strong simulations are used. We found that there is a tight tolerance of vertical crabbing angle at the interaction point in the HSR.

Luo, Y.↗
DOE OSTI2022

6-D ELEMENT-BY-ELEMENT PARTICLE TRACKING WITH CRAB CAVITY PHASE NOISE AND WEAK-STRONG BEAM-BEAM INTERACTION FOR THE HADRON STORAGE RING OF THE ELECTRON-ION COLLIDER

The Electron Ion Collider (EIC) presently under construction at Brookhaven National Laboratory will collide polarized high energy electron beams with hadron beams with luminosities up to 10^34 cm?^2 s^?1 in center mass energy range of 20-140 GeV. Crab cavities are used to compensate the geometric luminosity due to a large crossing angle 25 mrad in the EIC. It was found that the phase noise in crab cavities will generate a significant emittance growth for the hadron beams. The phase noise tolerance from the analytical calculation is very small for the Hadron Storage Ring (HSR) of the EIC. In this article, we present our preliminary numerical simulation results with a 6-d symplectic particle tracking to determine the proton emittance growth rate with crab cavity phase noise and beam-beam interaction for the HSR.

Luo, Y.↗
DOE OSTI2025

FPGA-Based Spill Regulation System for the Muon Delivery Ring at Fermilab

The Muon to Electron Experiment (Mu2e) requires a uniform beam profile from the Muon Delivery Ring to meet their experimental needs. A specialized Spill Regulation System (SRS) has been developed to help achieve consistent spill uniformity. The system is based on a custom-designed carrier board featuring an Arria 10 SoC, capable of executing real-time feedback control. The FPGA processes beam pulses of approximately 200 ns every 1.695 $μ$s, allowing for continuous monitoring of the extracted spill intensity through fast bunch integration. The system directly controls three quadrupole magnets, which work in conjunction with sextupole magnets to achieve third-order resonant extraction. Furthermore, the board interfaces with Fermilab's Accelerator Control Network (ACNET), enabling operators to modify spill regulation settings in real-time via the control network while providing diagnostic waveforms. These waveforms help operators monitor the process and fine-tune the feedback mechanisms. This paper presents an overview of the board's architecture and its initial progress toward regulating beam extraction. This initial version of the regulation system aims to evaluate baseline performance to inform future system improvements.

Berlioz, J. R. [Fermilab]↗
DOE OSTI2026

Mu2e resonant extraction regulation system simulation in delivery ring

Mu2e is an upcoming experiment at Fermilab that relies on the slowly extracted 8 GeV proton beam from the Delivery Ring. The experiment imposes strong requirements on the spill uniformity. To address these requirements, the fast spill regulations system is being developed and commissioned. To inform this development and optimize the system performance we are carrying out the detailed simulations of the regulation process. The simulation includes the effect of six harmonic sextupoles that excite the third-integer resonance and three fast ramping quadrupoles that drive the horizontal tune to 29/3. The components of spill regulation system are designed to mitigate long-term drifts in the beam, ensuring stable operation over extended timescales, as well as addresses rapid variations within single spill. In this study, we review the regulation system design, simulation of the slow regulation, and the fast regulation PID regulation to curtail random variations in the extraction rate that could occur within a single spill.

Narayanan, Aakaash [Fermilab]↗
DOE OSTI2025

Single-Bunch Instabilities at the Fermilab Recycler Ring

Understanding and characterizing collective instabilities is critical for high-intensity operation at the Fermilab Recycler Ring. This work presents an application of the the Nested Head-Tail (NHT) formalism for modeling single-bunch transverse instabilities, incorporating analytical solutions to the resistive wall impedances in the absence of space charge. Predicted growth rates and mode structures are benchmarked against PyHEADTAIL simulations and ongoing experimental measurements. The experimental program includes studies of bare-machine instabilities at different machine parameters. These results support the understanding of naturally-occurring instabilities in the Recycler and contribute to the development of predictive tools for beam stability in future high-intensity configurations.

Gonzalez-Ortiz, C. [Fermilab]↗
DOE OSTI2023

Design and Prototyping of the Electron Ion Collider Electron Storage Ring SRF cavity

Among the EIC?s numerous RF subsystems, the electron storage ring?s (ESR) 591 MHz fundamental RF system is one of the most challenging. Each cavity in the system will handle up to 2.5 A of beam current and supply up to 600 kW beam power under a wide range of voltage. The EIC R&D plan includes the design, fabrication and testing of such a cavity. In this paper, we will report the latest status and findings of the ongoing design and prototyping of this cavity, including the RF and mechanical/thermal design, fabrication design, and the progress of fabrication.

Guo, Jiquan↗
DOE OSTI2020

R&D toward a proof-of-principle experiment on optical stochastic cooling at the Fermilab’s IOTA ring

The stochastic-cooling method was invented in the late 70s and played a key role in the accumulation of intense beams of antiprotons for a head-on collision with counter rotating proton beams at 500 GeV in the Super Proton Synchrotron (SPS) at CERN. Such an improvement led to the discovery of the W and Z bosons in 1983. In brief, stochastic cooling relies on recording information (position) associated with short longitudinal slices within the bunch. The radiation is encoded on a radiofrequency (RF) signal, manipulated and used to correct the bunch slices at a later time.The repetitive correction is applied as the beam circulates in the ring ultimately cool the beam.Stochastic cooling has been successfully implemented in several machines for particle cooling and accumulation. Cooling of bunched beams in proton-(anti)proton colliders was challenging due to the high phase-space density of the bunches but was recently demonstrated at the Relativistic Heavy Ion Collider (RHIC).

43 PARTICLE ACCELERATORS↗
DOE OSTI2020

Modeling a ring magnet in ALEGRA

We show here that Sandia's ALEGRA software can be used to model a permanent magnet in 2D and 3D, with accuracy matching that of the open-source commercial software FEMM. This is done by conducting simulations and experimental measurements for a commercial-grade N42 neodymium alloy ring magnet with a measured magnetic field strength of approximately 0.4 T in its immediate vicinity. Transient simulations using ALEGRA and static simulations using FEMM are conducted. Comparisons are made between simulations and measurements, and amongst the simulations, for sample locations in the steady-state magnetic field. The comparisons show that all models capture the data to within 7%. The FEMM and ALEGRA results agree to within approximately 2%. The most accurate solutions in ALEGRA are obtained using quadrilateral or hexahedral elements. In the case where iron shielding disks are included in the magnetized space, ALEGRA simulations are considerably more expensive because of the increased magnetic diffusion time, but FEMM and ALEGRA results are still in agreement. The magnetic field data are portable to other software interfaces using the Exodus file format.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Design of electron storage ring for high-energy EIC cooling

We present a possible layout for an the Electron-Ion Collider electron cooler based on a storage ring which employs a wiggler section for the cooling of the electrons through radiation damping. We describe the optics, first and second order chromaticity correction and calculate the dynamic aperture. Finally, we estimate the damping times of the ion in EIC.

43 PARTICLE ACCELERATORS↗
DOE OSTI2021

Integrable optics design principles for beam halo suppression in accelerator rings at the intensity frontier

RadiaSoft LLC is collaborating with Fermilab to fundamentally advance the field of particle accelerator design, in order to reduce cost and technical risk for next-generation hadron accelerators, and to more rapidly advance the intensity frontier of high energy physics. The Fermilab PI is one of the originators of the theory of integrable nonlinear magnetic lattices. Fermilab is the only laboratory in the world pursuing the experimental verification of the theory. Transferring Fermilab expertise to RadiaSoft LLC will enhance US competitiveness by enabling US industry to engage in the design of future high intensity hadron rings for spallation sources, neutrino sources, muon sources, subcritical nuclear reactors and waste transmutation facilities.

43 PARTICLE ACCELERATORS↗
DOE OSTI2021

Transverse Beam Tails and Beam Lifetime in the EIC Electron Storage Ring

For most storage ring design purposes it is sufficient to assume a Gaussian distribution of the electrons in a bunch. However, a more detailed knowledge of the population in the transverse tails beyond a few sigma is necessary to predict the beam lifetime and the synchrotron radiation load in the interaction region due to beam-gas scattering and the beam-beam interaction. This report presents simulations to determine the required vacuum level as well as to serve as input data for detailed synchrotron radiation simulations.

43 PARTICLE ACCELERATORS↗
DOE OSTI2021

High current, high-temperature operation test of the superconducting magnets in the RHIC yellow ring

We report on the tests conducted at the end of RHIC Run 21 to evaluate the operation of superconducting magnets in the RHIC yellow ring at higher currents – up to 5500 A for the arc dipoles and all other magnets on the dipole bus and the focusing arc quadrupoles, up to 5750 A for defocusing arc quadrupoles and up to 6000 A for the insertion quadrupoles Q1 through Q9 – and higher temperatures – up to 5.1 K – than routine. None of the magnets quenched. This is an encouraging finding as the superconducting magnet coils could reach up to 4.9 K during operation with the 275 GeV EIC hadron beams.

43 PARTICLE ACCELERATORS↗
DOE OSTI2021

Data-driven Chaos Indicator for Nonlinear Dynamics and Applications on Storage Ring Lattice Design

A data-driven chaos indicator concept is introduced to characterize the degree of chaos for nonlinear dynamical systems. The indicator is represented by the prediction accuracy of surrogate models established purely from data. It provides a metric for the predictability of nonlinear motions in a given system. When using the indicator to implement a tune-scan for a quadratic Hénon map, the main resonances and their asymmetric stop-band widths can be identified. When applied to particle transportation in a storage ring, as particle motion becomes more chaotic, its surrogate model prediction accuracy decreases correspondingly. Therefore, the prediction accuracy, acting as a chaos indicator, can be used directly as the objective for nonlinear beam dynamics optimization. This method provides a different perspective on nonlinear beam dynamics and an efficient method for nonlinear lattice optimization. Applications in dynamic aperture optimization are demonstrated as real world examples.

43 PARTICLE ACCELERATORS↗